In recent years, a sense amplifier circuit having a cross-coupled inverter has been used as a circuit for reading minute signals such as data stored in a memory cell. In such a sense amplifier circuit, when there is a mismatch of threshold voltages of a pair of n-channel MOS transistors in the cross-coupled inverter, a reading error is more likely to occur. In other words, due to mismatched threshold voltages of the n-channel MOS transistors, the sense amplifier circuit may misread a “High” voltage as a “Low” voltage, and due to this misreading, the sense amplifier circuit latches inverted data.